/*
 * Copyright 2018 Autoware Foundation. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * v1.0 Yukihiro Saito
 */

#include "cluster_data_association/utils/utils.hpp"

namespace utils
{
double getArea(const autoware_perception_msgs::Shape & shape)
{
  double area = 0.0;
  if (shape.type == autoware_perception_msgs::Shape::BOUNDING_BOX) {
    area = getRectangleArea(shape.dimensions);
  } else if (shape.type == autoware_perception_msgs::Shape::CYLINDER) {
    area = getCircleArea(shape.dimensions);
  } else if (shape.type == autoware_perception_msgs::Shape::POLYGON) {
    area = getPolygonArea(shape.footprint);
  }
  return area;
}

double getPolygonArea(const geometry_msgs::Polygon & footprint)
{
  double area = 0.0;

  for (int i = 0; i < (int)footprint.points.size(); ++i) {
    int j = (i + 1) % (int)footprint.points.size();
    area += 0.5 * (footprint.points.at(i).x * footprint.points.at(j).y -
                   footprint.points.at(j).x * footprint.points.at(i).y);
  }

  return area;
}

double getRectangleArea(const geometry_msgs::Vector3 & dimensions)
{
  return double(dimensions.x * dimensions.y);
}

double getCircleArea(const geometry_msgs::Vector3 & dimensions)
{
  return double((dimensions.x / 2.0) * (dimensions.x / 2.0) * M_PI);
}
}  // namespace utils